(22-11-2018, 01:11 AM)Andynumpty Wrote: To be honest it is quite oily ?

An oil & filter change might help things. The breather is designed to create a vacuum in the crankcase so some condensed oil vapour is inevitable. As time goes on, the breather will probably get a bit less effective.
I've not seen any posts on cleaning the breather, but there may be some. There is a post on here somewhere about a mod to the breather pipe so that the turbo does not pull any air through the breather.

With a marine engine - it is worked at around 80% of its total power most of the time so as a result you get a lot of vapour coming from the rocker cover.

Normally it is ingested back into the open air filter via the turbo and back through the engine which burns it off. However it does have one side effect and can make the intercooler filthy.

A way round it is to fit a catch can, not unlike above but you must have the return feed going back to the intake in order to create a vacuum in the catch can.

Basically a pipe from the rocker cover going into the lid of the bottle then a pipe coming back from the lid of the bottle back to the intake. By the time the oil has reached the bottle it has cooled enough to drop into the bottle and the return pipe creates the vacuum.

Google Puke bottle and you'll see how its set up.

Alternatively, I use personally a system by Walker Engineering called an Airsep. These are fitted to many big diesels as it captures the oil vapour in a separate chamber within the filter and has an indicator to tell you when its full and when the filter is blocked.

yes the problem is diesels have no manifold vacuum, so they cant use the normal PCV systems that petrol engines use, so our crankcase breather is a simple vent
and when the bores are glazed and scored after 100k+ miles they vent like a steam engine, and that creates clogging problems (as in pic)
ideally you need a proper condensing catch can and then re-route it back into the intake, as above ^

"the clogging problem in the pic is caused by soot from the EGR system not the oil vent."

most of the exhaust goes through the exhaust mani and you dont get any of that soft carbon in the mani
a small proportion of exhaust gasses go through the egr (at idle and low load) so imo that soft carbon buildup in the inlet is "cooked" crankcase residue.
if the egr is deleted then that residue is simply burnt in the engine